Semiconductor processing reactor controllable gas jet assembly

ABSTRACT

A gas jet assembly includes a gas injector having a longitudinal axis, a first motor coupled to the gas injector and a second motor coupled to the gas injector. The first motor controls a position of the gas injector along the longitudinal axis of the gas injector. The second motor controls the angular position of the gas injector around the longitudinal axis of the gas injector.

FIELD OF THE INVENTION

The present invention relates generally to semiconductor processequipment. More particularly, the present invention relates to a gas jetassembly suitable for use in a semiconductor processing reactor and amethod of using the gas jet assembly.

BACKGROUND OF THE INVENTION

Semiconductor processing typically involved the formation of one or morelayers on a semiconductor substrate. For example, silicon epitaxy,sometimes called epi, was a process in which one or more layers ofsingle-crystal (monocrystalline) silicon were deposited on amonocrystalline silicon wafer.

To form a layer on a substrate, a process gas, typically a reactive gas,was introduced into a reactor containing the substrate. The process gasreacted to form the layer on the substrate.

As the art moves towards reduced feature size integrated circuits, ithas become increasingly important that the deposited layer has a uniformthickness. One primary parameter, which affected the thicknessuniformity of the deposited layer, was the flow characteristics of theprocess gas into and through the reactor. These flow characteristicswere controlled to a large extent by the gas injectors through which theprocess gas was introduced into the reactor.

To obtain the desired thickness uniformity, the gas injectors werecalibrated. Calibration was typically an iterative manual process inwhich a first layer was deposited on a first test substrate, thethickness uniformity of the first layer was measured, and the gasinjectors were manually adjusted in an attempt to improve the thicknessuniformity. A second layer was then deposited on a second testsubstrate, the thickness uniformity of the second layer was measured,and the gas injectors were again manually adjusted. This trial and errormanual procedure was repeated until the desired thickness uniformity wasobtained.

To allow the gas injectors to be calibrated in the above manner, the gasinjectors had to be readily and repeatably adjustable. Finn et al., U.S.Pat. No. 5,843,234, which is herein incorporated by reference in itsentirety, teaches a gas jet assembly in which the direction of a nozzleof the assembly was controlled by a positioning device. By manuallyadjusting micrometer knobs of the positioning device, the direction ofthe nozzle, and therefore the direction in which process gas wasintroduced into the reactor, was controlled.

To adjust the micrometer knobs of the positioning device, the person whooperated the reactor (the operator) had to physically go to thepositioning device and turn the micrometer knobs by hand. This requiredthe operator to leave the reactor controls temporarily unattended, whichwas undesirable. Further, turning the micrometer knobs by hand wasrelatively labor intensive and carried an inherent chance of operatorerror in micrometer knob adjustment.

The gas jet assembly of Finn et al. pivoted the nozzle relative to thereactor. Although allowing for pivoting of the nozzle, the gas jetassembly did not allow the nozzle to be moved in and out of the reactor.However, it is desirable to not only be able to control the direction ofthe process gas into the reactor, but also to be able to control thelocation within the reactor at which the process gas is introduced.

It was also important to avoid contamination of the reactor to allowhigh purity layers to be deposited. One potential source ofcontamination was the metal, e.g., stainless-steel, of the nozzle. Inparticular, the metal nozzle was often etched during processing, andthis etched metal contaminated the deposited layer. To avoid etching ofthe metal nozzle, shielding was used in an attempt to isolate the metalnozzle from the activated process gas in the reactor. Although theshielding was relatively effective, etching of the metal nozzle wasobserved depending upon the particular process performed.

SUMMARY OF THE INVENTION

In accordance with the present invention, a system in which a singlecomputer controls both a reactor and a gas jet assembly is presented. Inone embodiment, the gas jet assembly is mounted to the reactor such thata gas injector extends vertically up and into the reactor, i.e., thelongitudinal axis of the gas injector is vertical. The gas injectorincludes a bent tip which extends at an angle away from the longitudinalaxis of the gas injector.

Recall that in the prior art, the nozzle of the gas jet assembly waspivotable relative to the reactor. However, the gas jet assembly did notallow the nozzle to be moved in and out of the reactor. This limited theability to control the location within the reactor at which the processgas was introduced, and hence, limited the ability to control theprocess.

In contrast, the gas injector is readily moved in and out of thereactor, and rotated, by the gas jet assembly. Accordingly, greaterprocess control is obtained using the gas jet assembly in accordancewith the present invention than in the prior art

Further, in one embodiment, the operation of the gas jet assembly, andthus the angular and longitudinal positions of the gas injector, isbased on information supplied by an operator. Advantageously, the gasinjector is moved automatically without manual intervention.

Recall that in the prior art, the operator physically had to go to thepositioning device and turn micrometer knobs by hand to adjust thenozzle of the gas jet assembly. This required the operator to leave thereactor controls temporarily unattended, which was undesirable. Further,turning the micrometer knobs by hand was relatively labor intensive andcarried an inherent chance of operator error in micrometer knobadjustment.

In contrast, use of the gas jet assembly in accordance with the presentinvention eliminates the prior art requirement of manually adjustingmicrometer knobs. As a result, labor is saved and operator error isreduced. This, and turn, results in a lower overall operating cost ofthe reactor. Further, the gas jet assembly precisely controls thelongitudinal and angular positions of the gas injector. Accordingly, thedirection and position at which process gas is introduced into thereactor is precisely controlled.

In accordance with another embodiment of the present invention, a methodof controlling a gas injector in a reactor with a gas jet assemblyincludes selecting a first gas injector position for a first processoperation, e.g., for an etch cleaning of substrates in the reactor. Thegas injector is moved by the gas jet assembly automatically to the firstgas injector position without manual intervention. The first processoperation is performed.

A determination is made that a second process operation is still to beperformed. For example, the second process operation is a layerdeposition on the substrates. A new second gas injector position for thesecond process operation is selected. The gas injector is moved by thegas jet assembly automatically to the second gas injector positionwithout manual intervention. The second process operation is performed.

Thus, in accordance with the present invention, the gas injector ismoved to a gas injector position which provides the best results foreach process operation. In this manner, each process operation isoptimized. This is in contrast to the prior art where a single gasinjector position was used for all process operations, and the singlegas injector position was less than ideal depending upon the particularprocess operation.

In another embodiment, a first batch of substrates is processed. Adetermination is made that a second batch of substrates is still to beprocessed. The characteristics of the processed substrates from thefirst batch are measured, for example, the thickness uniformity of alayer deposited on at least one of the processed substrates is measured.Based on these measured characteristics, a new second gas injectorposition for the second batch of substrates is selected. The gasinjector is moved by the gas jet assembly automatically to the secondgas injector position without manual intervention. The second batch ofsubstrates is processed.

Advantageously, substrate characteristics from a previous batch are usedto optimize the gas injector position for the next batch. In thismanner, deviations in process conditions from batch to batch areautomatically compensated for resulting in consistent substrateprocessing from batch to batch.

In another embodiment, a process operation is initiated and a gasinjector is moved during performance of the process operation by a gasjet assembly. For example, the gas injector is rotated and/or moved inthe longitudinal direction.

In accordance with this embodiment, the operational conditions in thereactor are monitored during the process operation. The optimum gasinjector position is determined based on the monitored operationalconditions. The gas jet assembly moves the gas injector to the optimumgas injector position. The operational conditions of the reactor arecontinuously monitored, and the gas injector is continuously moved tothe optimum gas injector position during the entire process operation.

Thus, in accordance with the present invention, the gas injectorposition is responsive to the operational conditions existing in thereactor at all times. In this manner, instantaneous deviations inoperational conditions are automatically compensated for resulting inthe most optimum processing of the substrates.

In one embodiment, a gas jet assembly includes a gas injector having alongitudinal axis, a first motor coupled to the gas injector and asecond motor coupled to the gas injector. The first motor controls aposition of the gas injector along the longitudinal axis of the gasinjector. The second motor controls the angular position of the gasinjector around the longitudinal axis of the gas injector.

In one particular embodiment, the gas jet assembly includes a shaftsupport, a hollow shaft extending concentrically through the shaftsupport, and a slider movably supported on the shaft support. The firstend of the shaft is located within the slider and a gas injector iscoupled to the slider. During use, process gas is supplied to the shaft.The process gas flows from the shaft through the slider and into the gasinjector.

To use the gas jet assembly, a seal is formed between the slider and theshaft, e.g., with an O-ring. As set forth above, the gas injector iscoupled to the slider. The gas injector is moved by moving the sliderrelative to the shaft.

In other embodiments, a gas jet assembly includes a pivotable gasinjector. By having the ability to pivot the gas injector, greatercontrol of process gas introduction into the reactor is obtained.Further, the gas injector is formed of a nonmetallic material such asquartz, graphite or ceramic. By forming the gas injector of nonmetallicmaterials, contamination from the metal of nozzles of the prior art isavoided.

In the prior art, the gas jet assembly imparted significant stress onthe gas nozzle and so the gas nozzle was formed of metal to avoidcracking and failure of the gas nozzle. Recall that shielding was usedin an attempt to avoid etching of the metal nozzle and thus to avoidmetal contamination of the deposited layer. However, etching of themetal nozzle was still observed depending upon the particular processperformed.

Advantageously, the gas injector is pivotable and thus providesflexibility in controlling process gas flow characteristics into andthrough the reactor. Yet, the gas injector is formed of a nonmetallicmaterial thus avoiding metal contamination of the prior art. Inaddition, by forming the gas injector of an infrared transparentmaterial as those of skill in the art will understand, e.g., of quartz,heating of the gas injector is minimized thus minimizing depositformation on the gas injector.

These and other features and advantages of the present invention will bemore readily apparent from the detailed description set forth belowtaken in conjunction with the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is side view, partially in cross-section, of a gas jet assemblyin accordance with the present invention.

FIG. 2 is a cross-sectional view of the gas jet assembly along the lineII—II of FIG. 1.

FIG. 3 is a partial view, taken along the line III of FIG. 1, of the gasjet assembly illustrating the mechanism by which a stepper motorcontrols the angular position of a coupling ring.

FIG. 4 is a block diagram of a system in which a single computercontrols both a reactor and a gas jet assembly in accordance with thepresent invention.

FIGS. 5A, 5B are simplified side views of a reactor and a gas jetassembly in accordance with the present invention.

FIGS. 6A and 6B are block diagrams illustrating operations in a processfor which the gas jet assembly is used in accordance with alternativeembodiments of the present invention.

FIG. 6C is a diagram of a memory used by a computer in accordance withone embodiment of the present invention.

FIG. 7 is a block diagram illustrating operations in a process for whichthe gas jet assembly is used in accordance with another embodiment ofthe present invention.

FIGS. 8A and 8B are cross sectional views of gas jet assemblies havingpivotable injectors in accordance with alternative embodiments of thepresent invention.

FIGS. 9A and 9B are cross-sectional views of a pivotable injector inaccordance with an alternative embodiment of the present invention.

FIG. 9C is a perspective view, partially cutaway, of the pivotableinjector of FIGS. 9A and 9B.

In the following description, the same or similar elements are labeledwith the same or similar reference numbers.

DETAILED DESCRIPTION

In accordance with the present invention, a system (FIG. 4) in which asingle computer 400 controls both a reactor 133A and a gas jet assembly100A is presented. In one embodiment (FIGS. 5A, 5B), gas jet assembly100A is mounted to reactor 133A such that a gas injector 130A extendsvertically up and into reactor 133A, i.e., longitudinal axis 111A of gasinjector 130A is vertical. Gas injector 130A includes a bent tip 131A,which extents at an angle away from longitudinal axis 111A of gasinjector 130A.

Advantageously, gas jet assembly 100A controls both the angular andlongitudinal positions of gas injector 130A. For example, referring toFIG. 5A, tip 131A of gas injector 130A is moved from a first angularposition at position 504 to a second angular position at position 506.By controlling the angular position of gas injector 130A, gas jetassembly 100A controls the direction in which process gas is introducedinto reactor 133A.

As a further example, referring now to FIG. 5B, tip 131A of gas injector130A is moved upwards from a first longitudinal position at position 504to a second longitudinal position at position 508. By controlling thelongitudinal position of gas injector 130A, gas jet assembly 100Acontrols the location at which process gas is introduced into reactor133A.

Recall that in the prior art, the nozzle of the gas jet assembly waspivotable relative to the reactor. However, the gas jet assembly did notallow the nozzle to be moved in and out of the reactor. This limited theability to control the location within the reactor at which the processgas was introduced, and hence, limited the ability to control theprocess.

In contrast, gas injector 130A is readily moved in and out of reactor133A, and rotated, by gas jet assembly 100A. Accordingly, greaterprocess control is obtained using gas jet assembly 100A in accordancewith the present invention than in the prior art

Further, in one embodiment, the operation of gas jet assembly 100A, andthus the angular and longitudinal positions of gas injector 130A, isbased on information supplied by an operator. Advantageously, computer400 moves gas injector 130A automatically and without manualintervention.

Recall that in the prior art, the operator physically had to go to thepositioning device and turn micrometer knobs by hand to adjust thenozzle of the gas jet assembly. This required the operator to leave thereactor controls temporarily unattended, which was undesirable. Further,turning the micrometer knobs by hand was relatively labor intensive andcarried an inherent chance of operator error in micrometer knobadjustment.

In contrast, use of gas jet assembly 100A in accordance with the presentinvention eliminates the prior art requirement of manually adjustingmicrometer knob. As a result, labor is saved and operator error isreduced. This, in turn, results in a lower overall operating cost ofreactor 133A. Further, gas jet assembly 100A precisely controls thelongitudinal and angular positions of gas injector 130A. Accordingly,the direction and position at which process gas is introduced intoreactor 133A is precisely controlled.

In accordance with another embodiment of the present invention,referring now to FIGS. 5A, 5B and 6B together, a method of controllinggas injector 130A in reactor 133A with gas jet assembly 100A includesselecting a first gas injector position for a first process operation inan Injector Position Selection Operation 604A, e.g., for an etchcleaning of substrates 502. Gas injector 130A is moved automatically tothe first gas injector position by gas jet assembly 100A in a PositionInjector Operation 606A. The first process operation is performed in aPerform Process Operation 608A.

A determination is made that a second process operation is still to beperformed at an operation 614. For example, the second process operationis a layer deposition on substrates 502. Returning to Injector PositionSelection Operation 604A, a new second gas injector position for thesecond process operation is selected. Gas injector 130A is movedautomatically to the second gas injector position by gas jet assembly100A in Position Injector Operation 606A. The second process operationis performed in Perform Process Operation 608A.

Thus, in accordance with the present invention, gas injector 130A ismoved to a gas injector position which provides the best results foreach process operation. In this manner, each process operation isoptimized. This is in contrast to the prior art where a single gasinjector position was used for all process operations, and the singlegas injector position was less than ideal depending upon the particularprocess operation.

In another embodiment, referring still to FIGS. 5A, 5B and 6B, a firstbatch of substrates 502 is processed. A determination is made that asecond batch of substrates 502 is still to be processed at an AdditionalBatch Determination Operation 610A. The characteristics of the processedsubstrates 502 from the first batch are measured at a Measure SubstrateCharacteristics Operations 616. For example, the thickness uniformity ofa layer deposited on at least one of processed substrates 502 ismeasured. These measured characteristics are used as the batchidentifier at Batch Identifier Operation 602A. Based on these measuredcharacteristics, a new second gas injector position for the second batchof substrates 502 is selected at Injector Position Selection Operation604A. Gas injector 130A is moved by gas jet assembly 100A automaticallyto the second gas injector position without manual intervention. Thesecond batch of substrates 502 is processed.

Advantageously, substrate characteristics from a previous batch are usedto optimize the injector position for the next batch. In this manner,deviations in process conditions from batch to batch are automaticallycompensated for resulting in consistent substrate processing from batchto batch.

In another embodiment, referring now to FIGS. 5A, 5B and 7 together, aprocess operation is initiated at an Initiate Process Operation 701. Theoperational conditions of reactor 133A are monitored during the processoperation in an Operational Conditions Monitoring Operation 702. Theoptimum gas injector position is determined based on the monitoredoperational conditions in an Optimum Injector Position SelectionOperation 704. Gas jet assembly 100A moves gas injector 130A to theoptimum gas injector position in an Optimally Position InjectorOperation 706. Operations 702, 704, and 706 are repeated until theprocess operation is complete. More particularly, the operationalconditions in reactor 133A are continuously monitored, and gas injector130A is continuously moved to the optimum gas injector position duringthe entire process operation.

Thus, in accordance with the present invention, the gas injectorposition is responsive to the operational conditions existing in reactor133A at all times. In this manner, instantaneous deviations inoperational conditions are automatically compensated for resulting inthe most optimum processing of substrates 502.

In other embodiments, referring now to FIGS. 8A, 8B and 9A together, gasjet assemblies 800A, 800B, 900 include pivotable injectors 130B, 130C,130D, respectively. By having the ability to pivot injectors 130B, 130C,130D, greater control of process gas introduction into the reactor isobtained. Further, injectors 130B, 130C, 130D, are formed of anonmetallic material such as quartz, graphite or ceramic. By forminginjectors 130B, 130C, 130D of nonmetallic material, contamination fromthe metal of nozzles of the prior art is avoided.

In the prior art, the gas jet assembly imparted significant stress onthe gas nozzle and so the gas nozzle was formed of metal to avoidcracking and failure of the gas nozzle. Recall that shielding was usedin an attempt to avoid etching of the metal nozzle and thus to avoidmetal contamination of the deposited layer. However, etching of themetal nozzle was still observed depending upon the particular processperformed.

Advantageously, injectors 130B, 130C, 130D are pivotable and thusprovide flexibility in controlling process gas flow characteristics intoand through the reactor. Yet, injectors 130B, 130C, 130D are formed of anonmetallic material thus avoiding metal contamination of the prior art.In addition, by forming injectors 130B, 130C, 130D of an infraredtransparent material as those of skill in the art will understand, e.g.,of quartz, heating of injectors 130B, 130C, 130D is minimized thusminimizing deposit formation on injectors 130B, 130C, 130D.

More particularly, FIG. 1 is side view, partially in cross-section, of agas jet assembly 100 in accordance with the present invention. Gas jetassembly 100 includes an inlet plate 102, an outlet plate 104, and acentral housing 106, which connects inlet plate 102 to outlet plate 104.Inlet plate 102, outlet plate 104 and central housing 106 collectivelyform the outer housing of gas jet assembly 100.

A cylindrical shaft support 108 is fixedly attached to, and extendsthrough, inlet plate 102. O-ring 140 forms a gas-tight seal betweenshaft support 108 and inlet plate 102. In one embodiment, shaft support108 is attached to inlet plate 102 with screws.

Extending concentrically through shaft support 108 is a cylindricalhollow shaft 110, i.e., a hollow tube. In one embodiment, shaft 110 iswelded to shaft support 108 to form a gas-tight seal between shaft 110and shaft support 108. Although a separate shaft 110 and shaft support108 are set forth, in light of this disclosure, those of skill in theart will understand that shaft 110 and shaft support 108 can beintegral, i.e., can be one piece and not separate pieces connectedtogether.

At one end, shaft 110 is provided with a conventional process gasfitting 112 with which a gas-tight seal is formed with a process gasline (not shown). Shaft 110 has a common longitudinal axis 111 with agas injector 130.

A second end of shaft 110 is located within a slider 114. A first innercylindrical surface 119A of slider 114 is concentric with shaft 110. AnO-ring 116 is located in an O-ring channel 117 of inner cylindricalsurface 119A to form a gas-tight seal between shaft 110 and slider 114.Although O-ring 116 is set forth, those of skill in the art willunderstand that other seals besides O-rings can be used.

Slider 114 and, more particularly, a second inner cylindrical surface119B of slider 114, is movably supported on an outer cylindrical surface121 of shaft support 108 by a first bearing 118. Inner cylindricalsurface 119B is concentric with shaft support 108 and shaft 110. Slider114 is further supported on an inner cylindrical surface 123 of an innerhousing 122 by a second bearing 124. More particularly, a first outercylindrical surface 125A of slider 114 is moveably supported on innercylindrical surface 123 of inner housing 122 by bearing 124. Innercylindrical surface 123 of inner housing 122 and outer cylindricalsurface 125A of slider 114 are concentric with shaft 110 and have acommon longitudinal axis 111 with shaft 110.

As discussed in greater detail below, bearings 118, 124 allow slider 114to rotate about shaft support 108. Unless otherwise indicated, rotationrefers to rotation around longitudinal axis 111 in a plane perpendicularto longitudinal axis 111. Bearings 118, 124 also allow slider 114 tomove in the longitudinal direction. As used herein, the longitudinaldirection is the direction parallel to longitudinal axis 111 andlongitudinal motion is motion in the longitudinal direction. Althoughthe term parallel is used herein, those of skill in the art willunderstand that parallel means parallel to within manufacturingtolerances, i.e., that although various items may be described asparallel, the items may not be exactly parallel but only substantiallyparallel.

Slider 114 includes an injector coupling 128, which couples gas injector130 to slider 114. Injector 130 is a hollow tube, typically quartz,having a V-shaped end 132. V-shaped end 132 is typically formed bygrinding down, from opposing sides, the edge of a cylindrical end ofinjector 130. V-shaped end 132 is a locking feature, which insures thatinjector 130 is properly positioned in injector coupling 128. Injectorcoupling 128 has a V-shaped feature 129 complimentary to V-shaped end132 of injector 130. Injector 130 extends from injector coupling 128through a conventional seal 134 mounted to inner housing 122.

During use, process gas is supplied to shaft 110 through fitting 112.The process gas flows from shaft 110 through slider 114 and intoinjector 130. More particularly, the process gas flows through shaft 110and into an interior cavity 136 of slider 114. From interior cavity 136,the process gas flows through injector coupling 128 and into injector130. Injector 130 passes through a port 138 of a reactor 133 and directsthe process gas into reactor 133 through a tip 131 of injector 130,which in this embodiment is a bent tip. Although a particular injectoris described and illustrated, i.e., injector 130, in light of thisdisclosure, those of skill in the art will understand that a variety ofinjectors can be used. For example, injector 130 is curved, has aplurality of bends and/or is straight.

Generally, injector 130 is moved by moving slider 114 relative to shaft110. Since slider 114, and hence O-ring 116, move relative to shaft 110,leakage of process gas past O-ring 116 is possible. Since the processgas is often hazardous to human health and the environment, it isimportant that any leakage of process gas past O-ring 116 be avoided.Further, in the event that any process gas does leak past O-ring 116,this process gas must be captured and prevented from escaping to theambient environment.

Of importance, slider 114 is located within inner housing 122. Innerhousing 122 forms a gas-tight enclosure around slider 114 and thisenclosure captures any process gas which leaks past O-ring 116. Toinsure that this enclosure is gas-tight, an O-ring 137 forms a sealbetween inner housing 122 and inlet plate 102 and seal 134 forms a sealbetween inner housing 122 and injector 130. Thus, any process gas whichleaks past O-ring 116 is captured inside inner housing 122.

However, to prevent any process gas from leaking past O-ring 116 in thefirst place, a purge line 142 is plumbed into the enclosure formed byinner housing 122. Purge line 142 has a gas fitting 144 on a first endto which a gas-tight connection is formed with an inert gas line (notshown). A second end of purge line 142 extends through inlet plate 102and into the enclosure formed by inner housing 122. In one embodiment,purge line 142 is welded to inlet plate 102 to form a gas-tight sealbetween purge line 142 and inlet plate 102.

During use, an inert gas such as nitrogen is provided through purge line142 and into inner housing 122. By providing the inert gas at a pressuregreater than the pressure of the process gas, any leakage past O-ring116 is inert gas leakage into interior cavity 136 and is not process gasleakage out of interior cavity 136. Further, by providing the inert gasat a pressure greater than the pressure inside reactor 133, any leakagepast seal 134 is inert gas leakage into reactor 133 and is not processgas leakage out of reactor 133. An O-ring 139 is provided between port138 and inner housing 122 to prevent any direct leakage between reactor133 and the ambient environment. Thus, process gas leakage and theassociated hazards are avoided.

FIG. 2 is a cross-sectional view of gas jet assembly 100 along the lineII—II of FIG. 1. As shown in FIG. 2, shaft 110 extends concentricallythrough shaft support 108. Inner cylindrical surface 119B of slider 114is supported on outer cylindrical surface 121 of shaft support 108 bybearing 118.

Referring now to FIGS. 1 and 2 together, imbedded in slider 114 are aplurality of inner magnets 200A-200H. In particular, eight inner magnets200A-200H, collectively referred to as inner magnets 200, are imbeddedin slider 114. Inner magnets 200 are completely enclosed within slider114. Alternatively, surfaces of inner magnets 200 are exposed and areflush with, recessed from or extended from a second outer cylindricalsurface 125B of slider 114. Further, to avoid exposure of inner magnets200 to process gas, a sleeve 240, e.g., made of stainless-steel,encloses slider 114 including inner magnets 200.

Inner magnets 200 are arranged so that each of inner magnets 200 has amagnetic polarity opposite that of the adjacent magnets of inner magnets200. For example, inner magnet 200A is aligned with its north pole,south pole towards outlet plate 104, inlet plate 102, respectively.Conversely, inner magnets 200B, 200H are both aligned with their southpoles, north poles towards outlet plate 104, inlet plate 102,respectively.

A coupling ring 210 adjacent an outer surface of inner housing 122includes a plurality of outer magnets 212A-212H. In particular, eightouter magnets 212A-212H, collectively referred to as outer magnets 212,are imbedded in coupling ring 210. Outer magnets 212 are completelyenclosed within coupling ring 210. Alternatively, surfaces of outermagnets 212 are exposed and are flush with, recessed from or extendedfrom the inner surface of coupling ring 210.

Each of outer magnets 212 is located adjacent, and has a magneticpolarity opposite that of a different inner magnet 200, sometimes calleda corresponding inner magnet. For example, inner magnet 200A is alignedwith its north pole, south pole towards outlet plate 104, inlet plate102, respectively, and the corresponding outer magnet 212A is alignedwith its south pole, north pole towards outlet plate 104, inlet plate102, respectively.

Since opposite poles attract, inner magnet 200A is magnetically coupledto outer magnet 212A. More generally, each outer magnet 212A-212H ismagnetically coupled to its corresponding inner magnet 200A-200H. Sinceouter magnets 212 are imbedded in coupling ring 210 and inner magnets200 are imbedded in slider 114, coupling ring 210 is magneticallycoupled to slider 114 through inner housing 122. Accordingly, motion ofcoupling ring 210, e.g., rotation or longitudinal motion, produces anequal motion of slider 114.

Although eight outer magnets 212 and eight corresponding inner magnets200 are set forth, in light of this disclosure, it is understood thatmore or less than eight outer magnets 212 and corresponding innermagnets 200 can be used.

Advantageously, slider 114 is coupled to coupling ring 210 withoutphysically passing a structure through inner housing 122. In thismanner, the integrity and dependability of inner housing 122 as agas-tight enclosure is insured.

Referring again to FIG. 1, the longitudinal position, i.e., the positionalong longitudinal axis 111, of coupling ring 210 is controlled by astepper motor 160. Stepper motor 160 is attached to inlet plate 102. Apiston 162 extends from stepper motor 160 and through inlet plate 102.Stepper motor 160 controls the longitudinal motion of piston 162, andmore particularly, controls the retraction and extension of piston 162into and out of stepper motor 160.

Piston 162 is connected to a linear ring 164. Linear ring 164 isconnected to central housing 106 by linear bearings 166A, 166B, 166C,collectively referred to as linear bearings 166. As shown in FIG. 2,three linear bearings 166A, 166B, 166C are used although, in light ofthis disclosure, it is understood that more or less than three linearbearings can be used. Linear bearings 166 allow longitudinal motion oflinear ring 164 but prevent linear ring 164 from rotating. Thus, bycontrolling the longitudinal motion and the longitudinal position ofpiston 162, stepper motor 160 controls the longitudinal motion and thelongitudinal position of linear ring 164.

Longitudinal motion of linear ring 164 produces an equal longitudinalmotion of slider 114. In particular, referring to FIGS. 1 and 2together, linear ring 164 is connected to coupling ring 210 by bearings168A, 168B such that any longitudinal motion of linear ring 164 causesan equal longitudinal motion of coupling ring 210. As set forth above,coupling ring 210 is magnetically coupled to slider 114 such that anylongitudinal motion of coupling ring 210 causes an equal longitudinalmotion of slider 114.

Since injector 130 is coupled to slider 114, any longitudinal motion ofslider 114 causes an equal longitudinal motion of injector 130.Accordingly, stepper motor 160 is coupled to injector 130. In the abovemanner, stepper motor 160 controls the longitudinal motion andlongitudinal position of injector 130 and thus the location at whichprocess gas is introduced into reactor 133.

Recall that in the prior art, the nozzle of the gas jet assembly waspivotable relative to the reactor. However, the gas jet assembly did notallow the nozzle to be moved in and out of the reactor. This limited theability to control the location within the reactor at which the processgas was introduced, and hence, limited the ability to control theprocess.

In contrast, the longitudinal position of injector 130, and thus thelocation at which process gas is introduced into reactor 133, is readilycontrolled by gas jet assembly 100. Accordingly, greater process controlis obtained using gas jet assembly 100 than in the prior art.

The angular position around longitudinal axis 111 and in a planeperpendicular to longitudinal axis 111 (hereinafter the angularposition) of coupling ring 210, and hence injector 130, is controlled bya stepper motor 170. Stepper motor 170 is mounted to a bracket 172attached to linear ring 164. Thus, longitudinal motion of linear ring164 causes an equal longitudinal motion of stepper motor 170. Bracket172 extends through a slot 174 in central housing 106. Slot 174 has awidth sufficient to allow free longitudinal motion of bracket 172 inslot 174.

FIG. 3 is a partial view, taken along the line III of FIG. 1, of gas jetassembly 100 illustrating the mechanism by which stepper motor 170controls the angular position of coupling ring 210. Referring to FIG. 3,stepper motor 170 controls the rotation and angular position of aspindle 300 extending from stepper motor 170. A stepper motor sprocket302 on spindle 300 is attached to spindle 300. Alternatively, steppermotor sprocket 302 is integral with spindle 300, i.e., spindle 300 andstepper motor sprocket 302 are one piece and not separate piecesconnected together. A coupling ring sprocket 304 on coupling ring 210 isattached to, or is integral with, coupling ring 210. Stepper motorsprocket 302 is connected to coupling ring sprocket 304 by a belt 306.Typically, belt 306 is a chain and sprockets 302, 304 have teeth whichmesh with the links of belt 306.

Referring again to FIG. 1, bearings 168A, 168B allow coupling ring 210to rotate. This rotation is controlled by stepper motor 170, whichrotates spindle 300, stepper motor sprocket 302, and coupling ring 210via belt 306.

As set forth above, coupling ring 210 is magnetically coupled to slider114. Thus, rotation of coupling ring 210 causes an equal rotation ofslider 114. Since slider 114 is coupled to injector 130, rotation ofslider 114 causes injector 130 to rotate. Accordingly, stepper motor 170is coupled to injector 130. In this manner, stepper motor 170 controlsthe rotation (clockwise and counterclockwise) and angular position ofinjector 130.

Injector 130 includes bent tip 131, which extends at an angle away fromlongitudinal axis 111. Thus, the direction in which process gas isintroduced into reactor 133 is controlled by the angular position ofinjector 130 and hence by stepper motor 170.

Advantageously, gas jet assembly 100 controls both the angular andlongitudinal positions of injector 130. As discussed further below, theoperation of gas jet assembly 100, and thus the angular and longitudinalpositions of injector 130, is based on information supplied by theoperator.

Recall that in the prior art, the operator physically had to go to thepositioning device to turn micrometer knobs by hand to adjust the nozzleof the gas jet assembly. This required the operator to leave the reactorcontrols temporarily unattended, which was undesirable. Further, turningthe micrometer knobs by hand was relatively labor intensive and carriedan inherent chance of operator error in micrometer knob adjustment.

In contrast, use of gas jet assembly 100 in accordance with the presentinvention eliminates the prior art requirement of manually adjustingmicrometer knobs. As a result, labor is saved and operator error isreduced. This, in turn, results in a lower overall operating cost ofreactor 133.

Further, stepper motors 160, 170 precisely control the longitudinal andangular positions, respectively, of injector 130. For example, thelongitudinal position of injector 130 is controlled to within ±0.001inches (0.025 mm) and the angular position of injector 130A iscontrolled to within ±0°,0′,1″. Accordingly, the direction and positionat which process gas is introduced into reactor 133 is preciselycontrolled.

In an alternative embodiment, injector 130 is pivotally mounted toslider 114. FIG. 8A is a cross-sectional view of a gas jet assembly 800Ahaving a pivotable injector 130B in accordance with this embodiment ofthe present invention. Referring now to FIG. 8A, injector 130B includesa spherical ball portion 802A and a tube portion 804A extending fromball portion 802A. In this embodiment, ball portion 802A is integralwith tube portion 804A, i.e., ball portion 802A and tube portion 804Aare one piece and not separate pieces connected together.

Slider 114A includes a flange 806 having an annulus 808 perpendicular toa longitudinal axis 111B of slider 114A. An O-ring 810 forms a sealbetween annulus 808 and ball portion 802A of injector 130B. Moreparticularly, ball portion 802A is pressed into contact against O-ring810 towards annulus 808 by a compression ring 812. For example,compression ring 812 is threaded to slider 114A such that the forceexerted by compression ring 812 on ball section 802A is readilycontrolled by rotating compression ring 812.

Ball portion 802A includes an aperture 814. During use, process gasflows from interior cavity 136A, through aperture 814, through ballportion 802A, through tube portion 804A and into the reactor. O-ring 810insures that the process gas flows through injector 130B and not betweeninjector 130B and slider 114A.

FIG. 8B is a cross-sectional view of a gas jet assembly 800B having apivotable injector 130C in accordance with another embodiment of thepresent invention. Injector 130C of FIG. 8B is substantially similar toinjector 130B of FIG. 8A except that a ball portion 802B and a tubeportion 804B of injector 130C are separate pieces connected together.More particularly, tube portion 804B extends through ball portion 802B.In one embodiment, tube portion 804B is connected to ball portion 802Bthrough a fiction fit.

Advantageously, ball portion 802B can be formed of a material, e.g.,stainless-steel, having greater mechanical strength than tube portion804B, e.g., quartz. By forming ball portion 802B of a high-strengthmaterial, cracking and failure of ball portion 802B from force exertedby compression ring 812 is avoided. Alternatively, ball portion 802B isformed of the same material as tube portion 804B.

During use, process gas flows from interior cavity 136A, enters andflows through tube portion 804B of injector 130C and into the reactor.O-ring 810 insures that the process gas flows through injector 130C andnot between injector 130C and slider 114A.

Referring now to FIGS. 8A and 8B together, injectors 130B, 130C arereadily pivotable. More particularly, ball portions 802A, 802B,hereinafter collectively referred to as ball portion 802 for simplicityof discussion, are readily slidable against O-ring 810 and compressionring 812. For example, tube portions 804A, 804B, hereinaftercollectively referred to as tube portion 804 for simplicity ofdiscussion, are grasped and move to slide ball portion 802 againstO-ring 810 and compression ring 812. In this manner, injectors 130B,130C are pivoted around a pivot point 820A, 820B located within ballportions 802A, 802B, respectively. For example, injectors 130B, 130C arepivoted to locations 822A, 822B (shown in dashed lines) such thatinjectors 130B, 130C, respectively, are at an angle to longitudinal axis111B of slider 114A.

FIGS. 9A and 9B are cross-sectional views of a gas jet assembly 900having a pivotable nonmetallic injector 130D in accordance with analternative embodiment of the present invention. Referring now to FIG.9A, gas jet assembly 900 includes an inlet plate 904 and an outlet plate906. A cylindrical hollow shaft 902, i.e., a hollow tube, extendsthrough inlet plate 904 and is attached to inlet plate 904. For example,shaft 902 is welded to inlet plate 904. Shaft 902 is connected with aprocess gas line (not shown).

Inlet plate 904 and outlet plate 906 are connected together by a centralhousing 908, for example, with screws. An O-ring 910 forms a sealbetween inlet plate 904 and central housing 908. Similarly, an O-ring912 forms a seal between outlet plate 906 and central housing 908.

Sandwiched between inlet plate 904 and outlet plate 906 is a slider 914.Slider 914 includes a first half 916 and a second half 918 connectedtogether, for example, with screws. An O-ring 920 forms a seal betweenfirst half 916 and second half 918. Further, an O-ring 924 forms a sealbetween second half 918 and inlet plate 904. Similarly, an O-ring 928forms a seal between first half 916 and outlet plate 906.

Slider 914 defines a pocket 930 within slider 914. Located within pocket930 is a spherical ball 932, e.g., made of stainless-steel. An O-ring934 forms a seal between second half 918 and ball 932.

Attached to outlet plate 906, opposite slider 914, is an injectorhousing 940. An O-ring 942 forms a seal between housing 940 and outletplate 906. At one end of housing 940, housing 940, in combination with atapered seal ring 944, defines a pocket 949. Located within pocket 949is a ball 950 of an injector sleeve 952. Seal ring 944 has a threadedportion 946 which is threaded to housing 940. Seal ring 944 presses anO-ring 947 against ball 950 and thus securely supports ball 950 withinpocket 949 of housing 940. As discussed in greater detail below, ball950 is readily slidable against housing 940 and O-ring 947. O-ring 947forms a seal between ball 950 and housing 940.

Extending from ball 950 is cylindrical hollow shaft 954, i.e., a hollowtube, of injector sleeve 952. In this embodiment, shaft 954 and ball 950are integral. In accordance with this embodiment, injector sleeve 952 ismade of stainless-steel although in other embodiments injector sleeve952 is formed of other materials.

In accordance with this embodiment, injector 130D is formed of anonmetallic material such as quartz, graphite or ceramic. Injector 130Dis a straight tube which is inserted inside of injector sleeve 952, andmore particularly, extends through ball 950 and shaft 954 and,generally, injector sleeve 952. Shaft 954 of injector sleeve 952 extendsthrough ball 932. An O-ring 936 forms a seal between ball 932 and shaft954 of injector sleeve 952.

A piston 960 is movably supported within a piston housing 962. Pistonhousing 962 is connected to inlet plate 904 and outlet plate 906. AnO-ring 964 forms a seal between piston housing 962 and inlet plate 904,outlet plate 906. Further, an O-ring 966 forms a seal between piston 916and piston housing 962 although it is understood that more than oneO-ring can be used.

During use, piston 960 is moved within, and relative to, piston housing962. For example, piston 960 is moved by adjusting a micrometer 995attached to piston 960, as those of skill in the art will understand.Piston 960 includes a head 970 within a T-channel 972 of slider 914.Generally, piston 960 is coupled to slider 914. Accordingly, motion ofpiston 960 causes an equal motion of slider 114. Since ball 932 issupported in pocket 930 of slider 914, motion of slider 914 causes anequal motion of ball 932. Since shaft 954 extends through, and issupported in, ball 932, motion of ball 932 causes pivoting of injectorsleeve 952 around ball 932 and, more particularly, around a pivot point933 located within ball 932.

Since ball 950 of injector sleeve 952 is supported in pocket 949 ofhousing 940, motion of ball 932 also causes injector sleeve 952 to pivotaround ball 950, and, more particularly, to pivot around a pivot point953 located within ball 950. Since injector 130D is inserted intoinjector sleeve 952, injector 130D is similarly pivoted around ball 950and pivot point 953 and around ball 932 and pivot point 933. Generally,injector 130D is pivoted relative to housing 940 and is also pivotedrelative to slider 914.

As set forth above, injector 130D is pivotably coupled to housing 940and is also pivotably coupled to slider 914. More generally, piston 960is coupled to injector 130D. By controlling the motion and position ofpiston 960, pivoting of injector 130D is readily controlled. FIG. 9Billustrates pivoting of injector 130D such that injector 130D is at anangle to longitudinal axis 911 of shaft 902.

During use, process gas is supplied to shaft 902. The process gas flowsfrom shaft 902 through inlet plate 904 and into injector 130D. Housing940 includes a threaded cylindrical surface 980, which is threaded to aconventional gas ring (not shown), as those of skill in the art willunderstand. An O-ring 982 forms a seal between housing 940 and the gasring. Accordingly, injector 120D directs the process gas through the gasring and into the reactor.

FIG. 9C is a front perspective view, partially cutaway, of gas jetassembly 900 in accordance with this embodiment of the presentinvention. Referring to FIGS. 9A and 9C together, gas jet assembly 900includes piston 960, e.g., a first piston, and a piston 990, e.g., asecond piston, perpendicular to piston 960. Piston 990 is substantiallysimilar to, and operates in the same manner as, piston 960 and so is notdescribed in detail to avoid detracting from the principals of theinvention. Generally, piston 960 moves slider 914 in the horizontaldirection whereas piston 990 moves slider 914 in the vertical direction.Stated another way, piston 960 controls horizontal pivoting of injector130D whereas piston 990 controls vertical pivoting of injector 130D.

Advantageously, referring now to FIGS. 8A, 8B and 9A together, by havingthe ability to pivot injectors 130B, 130C, 130D, control of process gasintroduction into the reactor is obtained. Further, injectors 130B,130C, 130D are formed of a nonmetallic material such as quartz, graphiteor ceramic. By forming injectors 130B, 130C, 130D of a nonmetallicmaterial, contamination from the metal of nozzles of the prior art isavoided.

In the prior art, the gas jet assembly imparted significant stress onthe gas nozzle and so the gas nozzle was formed of metal to avoidcracking and failure of the gas nozzle. Recall that shielding was usedin an attempt to avoid etching of the metal nozzle and thus to avoidmetal contamination of the deposited layer. However, etching of themetal nozzle was still observed depending upon the particular processperformed.

Advantageously, injectors 130B, 130C, 130D are pivotable and thusprovide flexibility in controlling process gas flow characteristics intoand through the reactor. Yet, injectors 130B, 130C, 130D are formed of anonmetallic material thus avoiding metal contamination of the prior art.In addition, by forming injectors 130B, 130C, 130D of an infraredtransparent material as those of skill in the art will understand, e.g.,of quartz, heating of injectors 130B, 130C, 130D is minimized thusminimizing deposit formation on injectors 130B, 130C, 130D.

Referring again to FIG. 1, to allow pivoting of injectors 130B, 130C(FIGS. 8A, 8B), seal 134 is removed. In light of this disclosure, thoseof skill in the art will understand that a seal can be formed betweenslider 114 and inner housing 122, e.g., between outer cylindricalsurface 125A of slider 114 and inner housing 122, in a conventionalmanner to avoid leakage of the inert gas provided through purge line 142and into inner housing 122. Alternatively, a purge gas is not provided.

FIG. 4 is a block diagram of a system in which a single computer 400controls both a reactor 133A and a gas jet assembly 100A in accordancewith the present invention. Computer 400 is connected to reactor 133Aand gas jet assembly 100A. Computer 400 monitors various operationalparameters such as pressure and substrate temperature in reactor 133A.Computer 400 also controls the operation of reactor 133A, e.g., controlsthe heat source, gas flow rates and loading/unloading of the substrates,according to operator specified data stored in, or accessible by,computer 400.

In one embodiment, reactor 133A is a rapid thermal processing (RTP)reactor such as that described in Moore et al., U.S. Pat. No. 5,683,518,which is herein incorporated by reference in its entirety. Gas jetassembly 100A is selected according to the type of reactor 133A as thoseof skill in the art will understand. However, reactor 122A is notlimited to an RTP reactor but can be any one of a number of reactors,for example, is a vertical hot walled furnace reactor, a horizontal hotwalled furnace reactor, a chemical vapor deposition (CVD) reactor, anetch reactor, a flat panel display (FPD) reactor or an ion implantreactor.

In one embodiment, gas jet assembly 100A is a controllable gas jetassembly such as gas jet assembly 100 of FIG. 1. In accordance with thisembodiment, referring to FIGS. 1 and 4 together, computer 400 controlsthe operation of stepper motor 160 and thus the longitudinal position ofinjector 130 including tip 131. Further, computer 400 controls theoperation of stepper motor 170 and thus the angular position of injector130 including tip 131.

Computer 400 is a conventional digital computer and it is well withinthe skill of one skilled in the art of computer programming to programthe computer to accomplish the specific task in view of this disclosure.The particular digital computer utilized, the computer operating system,and computer program language utilized are not essential to theinvention and typically are determined by the process computer used withreactor 133A.

FIG. 5A is a simplified side view of reactor 133A and gas jet assembly100A in accordance with the present invention. Reactor 133A includes asusceptor 500 which supports substrates 502, e.g., silicon wafers. Gasjet assembly 100A is mounted to reactor 133A such that a longitudinalaxis 111A of injector 130A is vertical in the view of FIG. 5A, e.g., gasjet assembly 100 is rotated clockwise 900 from the view of FIG. 1. Gasjet assembly 100A is keyed to reactor 133A such that the orientation ofgas jet assembly 100A with respect to reactor 133A is precise.

Initially, injector 130A is located at a particular longitudinalposition, sometimes called an initial O,O Z axis starting setting, andat a particular angular position, sometimes called an initial O,O thetastarting setting. This position is identified as position 504. Referringto FIGS. 1 and 5A together, computer 400 controls stepper motor 170 torotate spindle 300. This rotates stepper motor sprocket 302, which movesbelt 306. Movement of belt 306 causes coupling ring sprocket 304, andhence coupling ring 210, to rotate. This rotation is magneticallycoupled to slider 114, which also rotates. Since injector 130A iscoupled to slider 114, referring now to FIG. 5A, injector 130A rotates.As a result, tip 131A of injector 130A rotates from its first angularposition at position 504 to a second angular position identified as aposition 506.

Although rotation of tip 131A in a first rotation direction isdescribed, e.g., in the clockwise direction when viewed from below, itis understood that computer 400 can rotate tip 131A in a secondrotational direction opposite the first rotational direction, e.g., inthe counterclockwise direction when viewed from below, by controllingstepper motor 170 to reverse the rotation of spindle 300.

The longitudinal position of injector 130A is also readily adjustable.Referring to FIG. 5B, initially, injector 130A is located at aparticular longitudinal position and a particular angular position,identified as position 504. Referring to FIGS. 1 and 5B together, toadjust the longitudinal position of injector 130A, computer 400 controlsstepper motor 160 to extend piston 162. This moves linear ring 164, andhence coupling ring 210, towards outlet plate 104. Since coupling ring210 is magnetically coupled to slider 114, slider 114 also moves in thelongitudinal direction. Since injector 130A is coupled to slider 114,referring now to FIG. 5B, injector 130A moves up and into reactor 133A.As a result, tip 131A of injector 130A moves from its first longitudinalposition at position 504 to a second longitudinal position identified asa position 508.

Although longitudinal motion of tip 131A in a first longitudinaldirection is described, e.g., in the upward direction from position 504to position 508, it is understood that computer 400 can move tip 131A inthe opposite longitudinal direction, e.g., in the downward directionfrom position 508 to position 504, by controlling stepper motor 160 toretract piston 162.

In FIG. 5A, injector 130A is rotated. In FIG. 5B, injector 130A is movedin the longitudinal direction. Further, in one embodiment, computer 400simultaneously rotates injector 130A and moves injector 130A in thelongitudinal direction by simultaneously controlling stepper motors 170,160, respectively (FIG. 1).

FIG. 6A is a block diagram illustrating operations in a process 600A forwhich gas jet assembly 100 is used in accordance with one embodiment ofthe present invention. Referring to FIGS. 4 and 6A together, from astart operation 601, the operator supplies the batch identifier, e.g.,inputs the batch identifier into computer 400, at a Batch IdentifierOperation 602 (hereinafter operation 602). As discussed in detail below,based on the batch identifier, in Injector Position Selection Operation604 (hereinafter operation 604), computer 400 determines the gasinjector position for the process. Unless otherwise indicated, gasinjector position refers to a particular angular position andlongitudinal position of a gas injector such as injector 130 of FIG. 1.As described herein, computer 400 performs certain functions and/or hascertain attributes. However, those of skill in the art will understandthat such functions and/or attributes result from execution ofinstructions by computer 400.

FIG. 6C is a diagram of a memory 650 used by computer 400 (FIG. 4) inaccordance with one embodiment of the present invention. Memory 650includes a batch ID table 652 and a process parameter database 654.Batch ID table 652 includes a plurality of batch ID records: batch ID1,batch ID2 . . . batch IDN (hereinafter batch ID records). Associatedwith each batch ID record are one or more process parameter records indatabase 654, e.g., the particular gases used, gas flow rates, andtemperatures. Of importance, at least one of these process parameterrecords is one or more of gas injector position records: gas injectorposition 1, gas injector position 2 . . . gas injector position N(hereinafter gas injector position records) contained in a gas injectorposition table 656. Gas injector position table 656 is contained withindatabase 654.

Thus, based on the batch identifier supplied by the operator, a batch IDrecord is selected from batch ID table 652. Based on the selected batchID record, one or more gas injector positions are selected from gasinjector position table 656. Referring now to FIGS. 4 and 6A together,computer 400 uses the information contained in the particular gasinjector position record to determine the appropriate gas injectorposition as set forth in operation 604. Thus, based on the batchidentifier supplied by the operator, a particular gas injector positionis selected for the process operation.

While a particular retrieval technique has been described using thebatch identifier, those of skill in the art will recognize thatequivalent functionality can be achieved using a look-up table, cachesor any other techniques that has data sets where each data set has aunique identifier.

Generally, any technique which provides a data set in response to thebatch identifier, e.g., a variable input, is used. Further, a widevariety of information can be used as the batch identifier. For example,information such as wafer size, desired growth rate and/or type ofprocess gas is used as part of the batch identifier.

In one embodiment, the batch identifier includes thickness uniformityinformation from the previous batch. For example, a conventional fouriertransform infrared (FTIR) spectrometer unit measures the thicknessuniformity of deposited layers on wafers from a previous batch. Thisthickness uniformity information is input as part of the batchidentifier.

In accordance with this embodiment, memory 650 in, or accessible by,computer 400 contains statistical data correlated to thicknessuniformity of deposited layers, e.g., in batch ID table 652. Forexample, this statistical data is obtained by performing a series oftest runs where thickness uniformities are measured for a series of gasinjector positions. To illustrate, the injector is moved in fixedincrements and the thickness uniformity is measured at each increment.Thus, for any particular thickness uniformity, the proper processparameters, including the proper gas injector position, to optimize thethickness uniformity for the next batch are retrieved from memory 650and used by computer 400 as set forth in operation 604.

To illustrate, the thickness uniformity of the last batch indicates thatthe deposited layer on the wafers is too thick near the edges of thewafers compared to the thickness near the centers of the wafers. Thisthickness uniformity information is input as part of the batchidentifier. Based on this thickness uniformity information, the propergas injector position to optimize the thickness uniformity for the nextbatch is retrieved from memory 650 and used by computer 400 as set forthin operation 604. For example, it may be determined that the injectorshould be extended in the longitudinal direction to a higher gasinjector position, e.g., moved from position 504 to position 508 of FIG.5B, to increase the thickness of the deposited layer near the centers ofthe wafers and decrease the thickness near the edges of the wafers.

In a Position Injector Operation 606 (hereinafter operation 606),computer 400 causes, i.e., generates a signal that in turn causes, theinjector to move to the gas injector position which was determined inoperation 604. Advantageously, the injector is moved automatically tothe gas injector position which was determined in operation 604 withoutmanual intervention.

In Perform Process Operation 608 (hereinafter operation 608), computer400 causes the process operation to be performed, e.g., causes heatingof the substrates and causes process gas to flow into reactor 133A sothat a layer is deposited on the substrates. The substrates are loadedinto reactor 133A as part of this process operation or, alternatively,are loaded prior to the process operation, e.g., are loaded beforeoperation 602.

At Additional Batch Determination Operation 610 (hereinafter operation610), computer 400 determines whether there are one or more additionalbatches of substrates which need to be processed. If not, then at EndOperation 612 (hereinafter operation 612), processing is complete andthe processed substrates are removed from reactor 133A.

However, if at operation 610, computer 400 determines that one or moreadditional batches of substrates are still to be processed, thenreturning to operation 608, the processed substrates are removed and newsubstrates are loaded into reactor 133A. Computer 400 causes the processoperation to be performed on the new substrates. Operations 608, 610 arerepeated until all batches of substrates are processed.

FIG. 6B is a block diagram illustrating operations in a process 620 forwhich gas jet assembly 100 is used in accordance with another embodimentof the present invention. Start Operation 601A, Batch IdentifierOperation 602A, Injection Position Selection Operation 604A, PositionInjector Operation 606A and Perform Process Operation 608A (hereinafteroperations 601A, 602A, 604A, 606A, 608A, respectively) of FIG. 6B aresubstantially similar to operations 601, 602, 604, 606, 608,respectively, of FIG. 6A and so are not discussed in detail to avoiddetracting from the principals of the invention.

Referring now to FIG. 6B, from operation 608A and at Additional ProcessOperations Determination Operation 614 (hereinafter operation 614),computer 400 determines whether there are additional process operationswhich still need to be performed. If at operation 614, computer 400determines that additional process operations are still required, then,returning to operation 604A, the next gas injector position for the nextprocess operation is selected. More particularly, computer 400determines the next gas injector position for the next processoperation.

For example, referring to FIG. 6C, computer 400 determines the next gasinjector position from a gas injector position record retrieved from gasinjector position table 656, i.e., a plurality of gas injector positionsare associated with the batch identifier. At operation 606A, computer400 causes the injector to move to the next gas injector position. Atoperation 608A, computer 400 causes the next process operation to beperformed. Operations 604A, 606A, and 608A are repeated until allprocess operations are completed.

As an illustration, the first process operation is an etch cleaning ofthe substrates. At operation 604A, computer 400 determines the first gasinjector position for the etch cleaning of the substrates. At operation606A, computer 400 moves the injector to the first gas injectorposition. At operation 608A, the substrates are etch cleaned.

At operation 614, computer 400 determines that a second processoperation is still to be performed. For example, the second processoperation is a layer deposition on the substrates. Returning tooperation 604A, computer 400 determines the new second gas injectorposition for this second process operation. This second gas injectorposition may be the same as, or different from, the first gas injectorposition for the first process operation. At operation 606A, computer400 causes the injector to move to the second gas injector position. Atoperation 608A, the layer is deposited on the substrate. At operation614, computer 400 determines that there are no additional processoperations to be performed.

Thus, in accordance with the present invention, the injector is moved toa gas injector position which provides the best results for each processoperation. In this manner, each process operation is optimized. This isin contrast to the prior art wherein a single gas injector position wasused for all process operations, and this single gas injector positionwas less than ideal depending upon the particular process operation.

If computer 400 determines that there are no additional processoperations which still need to be performed, then at Additional BatchDetermination Operation 610A (hereinafter operation 610A), computer 400determines whether there are one or more additional batches ofsubstrates which need to be processed. If not, then at End Operation612A (hereinafter operation 612A), processing is complete and theprocessed substrates are removed from reactor 133A. Although each batchis described herein as having a plurality of substrates, generally, abatch has one or more substrates.

However, if at operation 610A, computer 400 determines that one or moreadditional batches of substrates are still to be processed, then atMeasure Substrate Characteristics Operation 616 (hereinafter operation616), the processed substrate characteristics are measured. For example,the thickness uniformity of the deposited layer on a least one of theprocessed substrates is measured using a cluster tool layer thicknessmeasurement apparatus such as that described in Moore, U.S. Pat. No.5,872,632, which is herein incorporated by reference in its entirety.

After the processed substrate characteristics are measured, then atoperation 602A, these measured characteristics are used as the batchidentifier. Advantageously, computer 400 directly measures the processedsubstrate characteristics at operation 616 and uses these measuredcharacteristics in operation 602 automatically and without manualintervention. Alternatively, operation 616 is not performed, i.e., upondetermining that one or more additional batches of substrates are stillto be processed at operation 610A, batch identifier operation 602A isperformed.

At operation 604A, computer 400 determines the new gas injector positionfor the process (or for the first process operation of the process) forthe next batch of substrates. Of importance, the new gas injectorposition is based on the processed substrate characteristics from theprevious batch. At operation 606A, computer 400 causes the injector tomove to the new injector position, which was determined in operation604A. At operation 608A, computer 400 causes the process operation to beperformed. Operations 604A, 606A, and 608A are repeated until allprocess operations are complete on the new batch. Further, operations602A, 604A, 606A, 608A, 614, 610A and, optionally, operation 616 arerepeated until all batches of substrates are processed. For each cycle,processed substrates are removed and new substrates are loaded intoreactor 133A during one or more of operations 602A, 604A, 606A, 608A,614, 610A, 616, e.g., during operation 608A or 616.

Advantageously, processed substrate characteristics from the previousbatch are used to optimize the gas injector position for the next batch.In this manner, deviations in process conditions from batch to batch areautomatically compensated for resulting in consistent substrateprocessing from batch to batch.

As described above, the injector in accordance with the presentinvention is static, i.e., remains stationary during performance ofoperation 608A. In accordance with an alternative embodiment of thepresent invention, the injector is dynamic, e.g., rotates and/or movesin the longitudinal direction, during performance of operation 608A.

In one embodiment, the injector is continuously rotated in a firstdirection, e.g., clockwise or counterclockwise, during performance ofoperation 608A. In another embodiment, the injector is continuouslyrotated back and forth, i.e., rotationally oscillated, during operation608A. In either of these embodiments, optionally, the injector is alsocontinuously extended and retracted in the longitudinal direction, i.e.,is a longitudinally oscillated.

FIG. 7 is a block diagram illustrating operations in a process 700 forwhich gas jet assembly 100 is used in accordance with yet anotherembodiment of the present invention. Referring to FIGS. 4 and 7together, after the injector is moved into the proper position inoperation 606A (FIG. 6B), in an Initiate Process Operation 701(hereinafter operation 701), computer 400 initiates the processoperation. For example, computer 400 controls heating of the substratesand process gas flow into reactor 133A.

In an Operational Conditions Monitoring Operation 702 (hereinafteroperation 702), the operational conditions in reactor 133A are monitoredby computer 400 during the process operation. For example, the pressureinside of reactor 133A is measured using conventional techniques, e.g.,by one or more capacitance manometers. As a further example, thetemperature, such as substrate temperature, is measured usingconventional techniques, e.g., by a thermocouple.

In an Optimum Injector Position Selection Operation 704 (hereinafteroperation 704), computer 400 determines the optimum gas injectorposition based on the monitored operational conditions. To determine theoptimum gas injector position, memory 650 (FIG. 6C) in, or accessibleby, computer 400 contains statistical data correlated to operationalconditions. For example, this statistical data is obtained by performinga series of test runs where operational conditions are measured for aseries of gas injector positions. Thus, for any particular operationalcondition, the optimum gas injector position is retrieved from memory650 as set forth in operation 704. Although retrieval of the optimum gasinjector position from memory 650 is set forth, in light of thisdisclosure, those of skill in the art will understand that othertechniques to determine the optimum gas injector position for theparticular operational conditions can be used. For example, theparticular operational conditions are input as variables into a formulaused to calculate the optimum gas injector position.

To illustrate, temperature measurements obtained in operation 702indicate that a significant temperature gradient exists in reactor 133A.Based on these temperature measurements, computer 400 determines theoptimum gas injector position as set forth in operation 704. Forexample, it may be determined that the injector should be extended inthe longitudinal direction to a higher gas injector position, e.g.,moved from position 504 to position 508 of FIG. 5B, to decrease thetemperature gradient in reactor 133A and thus improve the thicknessuniformity of the deposited layer.

In an Optimally Position Injector Operation 706 (hereinafter operation706), computer 400 controls gas jet assembly 100A and moves the injectorto the optimum gas injector position determined in operation 704. In aProcess Operation Completed Determination Operation 708 (hereinafteroperation 708), computer 400 determines if the process operation iscomplete. If the process operation is complete, then the next operationis operation 614 in FIG. 6B.

If in operation 708, computer 400 determines that the process operationis not complete, then process flow returns to operation 702. Inoperation 702, computer 400 again monitors operational conditions. Basedon these monitored operational conditions, in operation 704, computer400 determines the new second optimum gas injector position.

For example, it may be the case that the injector was overextended,e.g., moved from position 504 to position 508 of FIG. 5B, to compensatefor an earlier existing first temperature gradient in reactor 133A andthat now an opposite second temperature gradient exists. Thus, computer400 determines that the injector should be retracted, e.g., referring toFIG. 5B, moved from position 508 to a location between positions 504,508, to a new second optimum gas injector position to decrease the nowexisting second temperature gradient and thus improve the thicknessuniformity of the deposited layer.

In operation 706, computer 400 controls the injector to move to the newsecond optimum position. Operations 702, 704 and 706 are repeated untilthe process operation is complete.

Thus, in accordance with the present invention, the gas injectorposition is responsive to the operational conditions existing in thereactor at all times. In this manner, instantaneous deviations inoperational conditions are automatically compensated for resulting inthe most optimum processing of the substrates.

This application is related to Moore et al., co-filed and commonlyassigned U.S. patent application Ser. No. 09/501,329, entitled “METHODFOR CONTROLLING A GAS INJECTOR IN A SEMICONDUCTOR PROCESSING REACTOR”,which is herein incorporated by reference in its entirety.

The drawings and the forgoing description gave examples of the presentinvention. The scope of the present invention, however, is by no meanslimited by these specific examples. Numerous variations, whetherexplicitly given in the specification or not, such as differences instructure, dimension, and use of material, are possible. The scope ofthe invention is at least as broad as given by the following claims.

We claim:
 1. An apparatus comprising: a shaft support; a hollow shaftextending concentrically through said shaft support; and a slidermoveably supported on said shaft support, wherein a first end of saidshaft is located within said slider.
 2. The apparatus of claim 1 furthercomprising a seal located in a channel of a first inner cylindricalsurface of said slider, said seal forming a gas-tight seal between saidshaft and said slider.
 3. The apparatus of claim 2 wherein said firstinner cylindrical surface is concentric with said shaft.
 4. Theapparatus of claim 2 wherein said seal is an O-ring.
 5. The apparatus ofclaim 2 wherein a second inner cylindrical surface of said slider ismoveably supported on an outer cylindrical surface of said shaft supportby a first bearing.
 6. The apparatus of claim 1 further comprising a gasinjector coupled to said slider.
 7. The apparatus of claim 6 whereinsaid slider comprises an injector coupling, said gas injector coupled tosaid slider by said injector coupling.
 8. The apparatus of claim 1further comprising a housing, said slider being located within saidhousing.
 9. The apparatus of claim 8 wherein said housing forms agas-tight enclosure around said slider.
 10. The apparatus of claim 8further comprising a purge line extending into said enclosure.
 11. Theapparatus of claim 8 further comprising a coupling ring magneticallycoupled to said slider through said housing.
 12. The apparatus of claim11 wherein said shaft has a longitudinal axis, said apparatus furthercomprising a motor which controls a position of said coupling ring alongsaid longitudinal axis.
 13. The apparatus of claim 11 wherein said shafthas a longitudinal axis, said apparatus further comprising a motor whichcontrols an angular position of said coupling ring around saidlongitudinal axis.
 14. An apparatus comprising: a gas injector having alongitudinal axis; a first motor coupled to said gas injector whereinsaid first motor controls a position of said gas injector along saidlongitudinal axis; and a second motor coupled to said gas injectorwherein said second motor controls an angular position of said gasinjector around said longitudinal axis.
 15. The apparatus of claim 14further comprising: a slider coupled to said gas injector; a housing,said slider located within said housing; and a coupling ringmagnetically coupled to said slider through said housing.
 16. Theapparatus of claim 15 further comprising a linear ring connected to saidcoupling ring by a bearing, said linear ring being connected to a pistonof said first motor.
 17. The apparatus of claim 15 further comprising: aspindle extending from said second motor; a stepper motor sprocket onsaid spindle; a coupling ring sprocket on said coupling ring; and a beltconnecting said stepper motor sprocket with said coupling ring sprocket.18. A method comprising: forming a seal between a slider and a shaft;coupling a gas injector to said slider; and moving said gas injector bymoving said slider relative to said shaft.
 19. The method of claim 18further comprising supplying process gas to said shaft, wherein saidprocess gas flows from said shaft through said slider and into saidinjector.
 20. The method of claim 18 wherein said gas injector has alongitudinal axis, said moving comprising moving said gas injector alongsaid longitudinal axis.
 21. The method of claim 18 wherein said gasinjector has a longitudinal axis, said moving comprising rotating saidgas injector around said longitudinal axis.
 22. The method of claim 18further comprising magnetically coupling a coupling ring to said slider,said moving comprising moving said coupling ring.
 23. The method ofclaim 22 wherein said gas injector has a longitudinal axis, said movingcomprising moving said coupling ring along said longitudinal axis with afirst motor.
 24. The method of claim 23 wherein said moving comprisingrotating said coupling ring around said longitudinal axis with a secondmotor.
 25. The method of claim 18 wherein said coupling comprisescoupling said gas injector to said slider with an injector coupling. 26.The apparatus of claim 6 wherein said gas injector is pivotably coupledto said slider.
 27. The apparatus of claim 26 wherein said gas injectorcomprises a ball portion and a tube portion extending from said ballportion.
 28. The apparatus of claim 27 wherein said ball portion andsaid tube portion are integral.
 29. The apparatus of claim 26 whereinsaid gas injector consists of a nonmetallic material.
 30. The apparatusof claim 26 wherein said gas injector comprises a material selected fromthe group consisting of quarts, graphite and ceramic.
 31. The apparatusof claim 15 wherein said gas injector is pivotably coupled to saidslider.
 32. The method of claim 18 wherein said gas injector ispivotably coupled to said slider.
 33. The method of claim 32 furthercomprising pivoting said gas injector.